Drill bit



Sept. 12, 1933. M. F. SENG 1,926,635

DRILL BIT Filed Nov. 19, 1932 Patented Sept. 12,1933 f a 1 q I i 1,926,635 r r DRILL BIT Application November 19,, 19s

Serial No. 643,493

it 2 Claims. (01. 255-69)" This invention relatesto improvements in drills which thevupper onesoff the cutting blades are or faugers and pertains particularly to a drill located; i v a h to I a designed for use in coal mines ,7 t L Figure f1: isa view in bottom plan oftheauger The primary object of th e present invention shown in the position of Figure 3.

g 5 is to provide a drill bit formed in aIsolid piece Referring now more particularly to the draw- 60 anclfso designed as to eliminate frictional coning wherein like numerals or reference indicate; tact withgthe wall of the drilled hole except corresponding partsthroughoutthe several views, at' those' points of the. bit which are actually the *n'umerall indicates generally a, portion of.

theforwardend of an auger which forward 7 cutting into the mineral. 7

Another object'o f the invention to provide" end provided with an interiorly threaded socket an improved cast or.forged drill bitlhaving a, 2 into which thethreaded stem portion 3 of the a cutting centering tip or point at its head whereby bit embodying thepresent invention isrmounted, V a better directional control of the same, and the Thebitlisindicated asawholebythe numeral l, auger to which it i connected,will behad by th As is'clo rly shown the ow e d he aug r operator. 1 T 5 t a 1 which has the, relativelyilat'pitched spirals,

Still another object of the invention is to pro-- terminates in Cy in po n W Q vide a drill bit and auger in which the bit is the threaded bore iris-formed. The rear end formed to cut a bore of greater diameter than -Y t bit f is f i i fc s ctio ,7 the auger so that the bore 01'11018 will not become as indicatediat 6 and is of the same overall diaml choked'h the cuttings but'may be freel moved t asit e p t 5 o se o t w 75.1

out by the auger. a i the bit is mounted on the augerthe abutting A still further object of the invention is to p rtions will have h ir s rf e flush. n n provide an improved cast or forged "drill bit d es o shou d s-w h W111 11+ adapted to be detachably coupled with an auger tact With t meteriai Which is o dvaway and r and formedjat its forward orhead end'to pfothus retard the forward movement of the auger. w

vide a plurality of outwardly flared cutting blades I' he: forward or head end oi the drill bit is which together with a centering tip form a coneformed to lJ'TOVide' e Outer blades .7 and the shaped bottom in a, drill hole, which cuttingpinner blades 8. These outer blades 7 extend torerationpermits of the more. ready cutting away ir Y- d fl at l y a h wn and y "30' of the substance being drilled and the formation are also longitudihally curved h the st of the cutting blades giving a bore of greater ting edge 9 he are directed 'circumferen Width n the auger so that the binding or tially of the auger and inthe direction'of rotation j frictional engagement oftheauger in the bore 9 t same and b e t is prevented 7 7 As is clearly shown the cutting edges of the The invention will be best understood from Outer blades are formed by a u y tap 9 0 a consideration oi the following detailed descripmg or decreasingthe thickness t t tion taken in connection with the accompanying fi ggi g g 3; g s i ii sf g ig ggg igig g gg gigi g g of the dull bit and crossing upon the line thereof.

. The inner blades 8 are formed from a portion 71S mt Pi lanfstrict cmformity with 10 of the bit which is located between the blades the Showmg of the drawmg but may be changed a 7 and this portion is turned so that its lower t or modified so long as such changes or modifican extends substantiauy in km t right tle s mar o at r ep from the angles to the plane occupied by the blades! and, 5v lient features of the invention as expressed in has the blades 8 formed therefrom. The blades t pp e 1 m o 8 flare outwardly as shown in Figure -3 so that y In raw s I there is formed therebetween a crotch '11, and Fi ure 1 i a vi w in side v ti n of the they are longitudinally curved so that their cut n an embodying th pr n i v n i n, ting edges 12 are. directed substantian in the 50'. viewing the same from the side of the lowermost direction of rotation of the bit like the edges 9' cutting blades; Q I of the outer blades 7; V i Figure 2 is a view in end elevation of the Integral with the center part 10 of the bit] blt i the Position Shown Figure l; from which the blades 8 are formed, isa center- Figure 3 is a view in side elevation of theing spur or: point 13 which extends downwardly '55 bitand auger viewing the bit from the side upon y from the crotch 11 between the blades8. and terno I minates slightly. below the lowest points of the blades betweenwhich it positions.

The edges 12 of the blades 8 are disposed to extend in, a line oblique to the longitudinal axis of the bit and. auger and coact with the edges 9 of the outer blades to .form a cone-like bottom for thedrilled hole. The centering spur or tip 13 isrturned or twisted slightly on its long axis so as to present cutting edges 14. g

From the foregoing it-will be readily apparent that an auger equipped with-a drill bit of the character herein" described canbe readily driven into a body of coal or any other body. ofmineral.

as the bit upon the forward endthereof cuts a auger thereby preventing any binding :of the auger in the hole. 7 Y

Due to the peculiar formation and disposition:

of the cutting blades a more rapid-cutting action is obtained thanwith vother types 'of'bits and-in addition-the provision of the centering tip or spur between the forward innrwblade's 8 enables the operator to keep the drill moving-along a straightfline or, in other words, properly-bentered.

aving thus described the-invention what; is claimed is':-

1, 1; drill bit forcoal or ot r 'rnineralsncorm prising an elongated;body forinedat oneend to 7 provide an louter pair of euttingblades'and' an inner pair-of cutting bladesgsaid outer pair of blades being diametrically oppositely dispo'sed and fia'ring outwardly from the'bodyat theirfree ends'fand further'being'curved' tohave their free ends directed I in the, directionof rotation I of the bit, the-"said free-ends being sharpened to 'provide cutting edges, said inner blades extending downwardly from between the outer blades and having their free ends sharpened to provide cutting edges and further flared to extend laterally in a plane substantially at right angles to the,

plane of theouter blades, said inner blades beingcurved to havetheir cutting edges directed in the direction of rotation of the bit,-and acentering point extending longitudinally of the bit between the inner blades and projecting beyond the same.

' 2. A drill bit for coal or other minerals, comprising an elongated body formed at one end to provide an outer pair of cutting blades and an inner pair of cutting blades, said outer pair of blades being diametrically oppositely "disposed and =flaringfoutwardly from the body at their 1 free ends and further being curved to have their free-ends directed in the direction of rotation of the bit, the said free endsbeing sharpenedto provide cutting edges, saidii'nner blades extendingi downwardly from jbetween'jthe outer blades and having. their free 'endssharpened to provide cutting edges and furtherfflared to extend "laterally in a, plane substantially at right angles to the plane of the outerblades, said inner, blades being curved to'have their cutting edges directed in thedire'ction of rotation of the bit, a centering point extending longitudinally'of the bit between the inn'erblades and projectingbeyond the same, said blades having their edges disposed atv an oblique angle to the length' of the bit and arranged so that} projections of said edges meet at a common point on the longitudinal center of the bitand said innerblades beingposition'ed' ;in advance of the outer blades.

j MATTHEW sENG, 

